Practice 3 Report - Only third best

Lewis Hamilton posted the quickest lap times in both of Friday's practice sessions, but he had an off day on Saturday and was only third best in Free Practice 3 behind Sebastian Vettel and Valtteri Bottas.

The ambient temperature at the start of the 90-minute session was 81 degrees Fahrenheit (27 degrees Centigrade) and the track temperature was 93 degrees Fahrenheit (34 degrees Centigrade.)

After practicing on Friday, however, Wehrlein declared he did not feel fit enough to drive a full race distance. Reserve driver Antonio Giovinazzi, 23, took over the Sauber C36 and will make his F1 racing debut in the Australian Grand Prix.

"My fitness level is not as it should be for a full race distance because of my training deficit," Wehrlein said. "I explained the situation to the team yesterday evening. Therefore, the Sauber F1 Team has decided not to take any risks. It is a pity, but the best decision for the team."

Wehrlein suffered back injuries in a crash in the Race of Champions in January, and he had to sit out the first of the two preseason tests.

Giovinazzi will become the first Italian to take part in a world championship grand prix since Tonio Liuzzi and Jarno Trulli raced in the 2011 Brazilian Grand Prix.

Fit as a fiddle Hamilton was quickest in both Friday practice sessions in Australia.

"After struggling with some issues in Barcelona testing, we didn't know if we'd have the same thing here," the Mercedes driver said. "What's really encouraging is that we've arrived at the track just a week later and the car is exactly where it should be. It's feeling great out there and the guys have done a fantastic job. We've shown good form so far on both the long and short runs and we got every lap done that we wanted to. The tires performed really well too."

Grosjean was the first out on track in FP1 and FP2 on Friday, and he repeated that in FP3 on Saturday.

Ricciardo, on the super soft Pirelli slicks, set the first time: 1:25.589. Then Raikkonen, on the ultra soft compound, shaved 0.715 of a second off of that with his lap in 1:24.874. Vettel, also on the ultras, got down to a 1:24.308. He then lowered that to a 1:23.989.

Raikkonen slowed because of a punctured left rear tire, and for some reason his Ferrari shut down. He got it going again and returned to the pits.

Twenty minutes into the one-hour session, Hamilton and Bottas had yet to set a time. Nor had six other drivers. Vettel, Raikkonen, Ricciardo, Sainz, Kvyat, Massa, Verstappen, Perez, Ocon and Stroll topped the list of those who had clocked a lap.

Twenty-three minutes into the session, Bottas moved into second place with a 1:24.628 using the super soft Pirellis. And now Hamilton was on his warmup lap. Also on the super softs, he displaced his teammate in second with a 1:24.542.

Just past the midpoint of FP3 Ricciardo did a run on the ultra soft compound that yielded a time of 1:25.124, and he stayed fifth even when he improved to a 1:25.092.

Raikkonen's second run on the ultras ended with him 0.001 of a second faster than Vettel.

Vettel was on his out lap with twenty-three minutes remaining in the session. His next tour was a fast one as he clocked a 1:23.380 on the ultras.

So now the fans waited to see what the Mercedes drivers could accomplish on the ultra soft tires.

Bottas went first and grabbed a 1:23.859. Hamilton's lap was not all that good 1:23.870 so he was third behind Vettel and Bottas.

The rest of the top 10, with 15 minutes remaining, were: Raikkonen, Ricciardo, Grosjean, Sainz, Kvyat, Magnussen and Hulkenberg.

With just over 10 minutes to go, Stroll hit the wall with the right rear and then right front side of his Williams and then stopped at Turn 11. That brought out the red flags.

The session was not restarted. The top 10 at the end of FP3 : Vettel, Bottas, Hamilton, Raikkonen, Hulkenberg, Ricciardo, Grosjean, Sainz, Kvyat and Magnussen. Giovinazzi was 20th and 5.2 seconds slower than Vettel.